“Supernatural” is used more in reference to phenomena than to “things” with objective reality. I personally see no reason to classify some phenomena as supernatural. There are aspects to reality that are not understood and can never be understood with our illusory space/time/matter model, but because they are not understood does not mean they are not natural. Everything is natural.

But you are speaking in terms of existence and non-existence. My opinion is that humans do not understand existence on a deep level. We detect a certain pattern in the fluctuating morass of sensory data, and if that pattern is detected often we give it a name or icon and promote it to the status of a “thing”. All those objective things out there exist only in our thoughts. There is ultimate reality beyond, but we can not directly detect or understand ultimate reality, which has nothing to do with space, time, causality, etc.

I agree that the supernatural is not a useful concept, but it’s not an issue of existence vs. non-existence. Existence is in the mind. Love exists. Waterfalls exist. The US exists. But all those are concepts, not objective things.

“As Wheeler put it, “No space. No time. Heaven did not hand down the word ‘time’. Man invented it. . . . If there are problems with the concept of time, they are of our own creation . . . as Einstein put it ‘Time and space are modes by which we think, and not conditions in which we live.’ ”30”

— The Case Against Reality: Why Evolution Hid the Truth from Our Eyes by Donald Hoffman
[a.co]

Put, hopefully, more simply, the supernatural exists exclusively in the space between the ears of humans.

Nature is more than the physical and space time. According to quantum gravity theory time does not exist and space is not the smooth expanse that we envision. We perceive reality through the lens of our illusory space/time/matter model, but ultimate reality beyond is of an entirely different order of existence and is beyond our grasp.

“Supernatural” is not a useful concept. Everything is natural but there are aspects of nature that we can not understand and may never understand.

I suggest this is a play on terms rather than erudite conjecture.

Would a mobile phone not be considered supernatural to a Roman senator?

Does metaphor exist?